Ready-To-Eat ("R-T-E") cereals are popular packaged goods food items and exist in a variety of forms including flakes, shreds, biscuits and puffed pieces. The present invention provides an improvement in R-T-E cereals especially in flake form.
Conventionally, R-T-E cereals in the form of flakes are prepared by preparing a cooked cereal dough, forming the cooked cereal dough into pellets of desired moisture content, forming the pellets into wet flakes and toasting wet cereal flakes. The toasting causes a final drying, a tenderizing and slight expansion of the R-T-E cereal flakes. The final flake cereal attributes of appearance, flavor, texture, inter alia, are all affected by the selection and practice of the steps employed in their methods of preparation.
Current consumer trends favor more natural appearing foods including R-T-E cereals. For flaked R-T-E cereal products, particularly whole grain multi grain cereals, a flake having the appearance of bits of intact grain pieces are desirable. However, providing such a flake R-T-E cereal product presents numerous difficulties.
To provide flake cereals having this desired appearance feature, one approach is to topically apply cereal bits onto the surface of the flake either prior to toasting or as part of a sugar coating after toasting. However, it would be desirable to have the flake itself exhibit the desired appearance of having discernible grain bits as part of the cereal flake.
Since high shear during cooking tends to destroy grain bit integrity, one technique is to use low shear long residence time batch cookers to prepare a cooked cereal dough. While useful, such machines are expensive. Also, due to their long cooking cycles, the throughput of such cooking machines is low. Current R-T-E cereal production trends increasingly rely upon continuous cooker extruders, especially twin screw extruders to provide faster throughputs.
While cooker extruders are economically desirable due to their high output and short residence or cooking times, and continuous operations features, cooker extruders tend to impart high amounts of shear to the cooked cereal dough formed therein. The high shear tends to destroy the grain piece bit integrity sought herein. The extruder's screw configuration and operating conditions can be selected to minimize the amount of shear imparted to the cereal dough. For example, the extruder can be configured to minimize the amount of time within the extruder and thus to some extent the amount of shear experienced. However, low shear and short extruder residence times can in turn lead to a problem of "white tips" within the cereal dough. White tips are small visually unappealing white spots within the cooked cereal dough which have been incompletely cooked or dispersed within the cereal dough. The problem of white tips is more severe with whole wheat or whole wheat containing cooked cereal doughs as compared, for example, to whole rice.
One attempt at solving the problem of white tips in cooker extruder prepared whole wheat containing cooked cereal doughs is given in U.S. Pat. No. 4,790,996 entitled "Process For Preparing Cereal Products" (issued Dec. 13, 1988 to Roush; et al.). The '996 patent teaches adding a hollow pipe to the discharge end of a cooker extruder to cook the dough more by virtue of an extended residence time thereby reducing white tips.
The present invention provides further advances and improvements in the art of preparing R-T-E cereals especially in flake form containing whole wheat that desirably exhibit discernible grain bits. The R-T-E cereals exhibit minimal white tips and have low imparted shear to the cooked cereal dough from which they are prepared.
The present improvements reside in part in the steeping of the cereal grains under particular conditions prior to being formed into a cooked cereal dough in a cooker extruder. After being formed into a cooked cereal dough, the dough is subjected to a step within a second, low shear extended residence time cooker.